The transfer of information over computer networks has become an increasingly important means by which institutions, corporations, and individuals communicate and conduct business. Computer networks have grown over the years from independent and isolated entities established to serve the needs of a single group into vast Internets that interconnect disparate physical networks and allow them to function as a coordinated system. Currently, the largest computer network in existence is the Internet. The Internet is a worldwide interconnection of computer networks that communicate using a common protocol. Millions of computers, from low end personal computers to high end super computers, are connected to the Internet.
Many network operators, such as operators of commercial websites on the Internet, have reason to determine the validity of a given user interaction with the network or website. For example, with the recent growth of commercial enterprises conducting business on the Internet, a website operator may want to determine which interactions users have with the website are invalid or even criminally fraudulent. Measures of uniqueness and authenticity, such as user cookie, client IP address, or user agent identification are mechanisms that can at times be easily thwarted.